'Active' weather — Neighboring counties Davis and S.L. differ widely in weather

Published: Friday, Feb. 10 2006 12:00 a.m. MST

The power of east canyon winds topple huge electrical transmission towers in Kaysville in April 1983.

The date is Jan. 2, 2006, and it has been raining in Davis County for more than four hours. However, Salt Lake City is still dry and remained so until late morning. Why this significant difference in weather?

According to Mark Eubank, KSL's chief meteorologist and Bountiful resident for more than three decades, weather differences between the two counties can be surprising.

"The Salt Lake Valley has a 'rain shadow,' " Eubank said.

This means the Oquirrh Mountains are believed to somehow shield Salt Lake County from many storms as south winds blow.

Even some snowstorms that plaster Davis County might only create a skiff of snow in downtown Salt Lake City.

Davis County weather is unusual, to some degree, and Eubank said that's true for just about everywhere in Utah. If the state were flat, without mountains, its weather would be uniform. However, every little valley has its own differences, thanks to the local mountains.

The Great Salt Lake is another variable, and its warm waters in winter can be as effective as a mountain in creating weather.

Salt Lake and Davis counties have different "lake effects" too.

Eubank said Beck Street, the narrow corridor at the north end of Salt Lake County before Davis territory begins, is a sort of "convergence zone," where weather can change one way or other.

The hot springs in that area, combined with the oil refineries there, can also affect weather. Fog sometimes is worse on Beck Street than any other location in that area.

Cloud seeding during fogged-in days at the Salt Lake International Airport can also put light snow on the ground in North Salt Lake and the Beck Street area when it exists nowhere else along the Wasatch Front.

Eubank said he chose to live on the east bench in Bountiful because of its "active, fun weather."

He said the Bountiful bench receives about 28 inches of water a year — or about three times the statewide average. That's more moisture in a given year than San Francisco, which averages 20.4 inches.

Utah may be mostly a desert, but Bountiful's bench doesn't act that way.

The 31-year average for annual snowfall at Eubank's house is 124 inches. That compares to just 27.46 inches a year at the Salt Lake City International Airport, about seven miles away. Admittedly, Eubank's house is 4,990 feet above sea level, or some 600-plus feet above the valley floor, but that 124 inches would be coveted by many ski resorts outside Utah.

Bountiful is also a place where the mountains indent to the east to form a cove, of sorts, and Eubank said that factor may also intensify snowfall in that area.

High-velocity east winds are also another special characteristic of Davis County's weather. Davis can have stronger east winds than other portions of the Wasatch Front.

"Davis County is in the heart of the canyon winds," Eubank said, explaining that equals winds strong enough to blow over trains, or rip off roofs.

That's because of the usual way a high pressure sets up in western Wyoming and the winds get funneled strongest through Davis County.

East canyon winds have been clocked as high as 120 mph in Davis County.

Eubank also admits Davis County is now overdue for an east canyon wind episode. They used to occur on average every 18 months — usually in the spring or fall — but we have not suffered any since November 2003 and the last time 100 mph winds hit the valleys of Davis County was back in 1988.